This invention relates to improved flexible joint assemblies having a variety of uses, such as lawn mower drag shields, door seals and the like.
Where lawn mowers are concerned, since they employ a high speed rotary cutter, they are required to have a drag shield which protects the users' legs and feet from being injured by loose objects which may be propelled rearwardly during operation of the mower. In the usual case, the drag shield trails behind the mower as it is moved forward, but when pulled backward the shield inhibits the mower's maneuverability. Ultimately, the shield becomes torn, or is otherwise broken off of the machine.
One known type of shield includes a plurality of separate, and extruded plastic strips or panels which are bonded together along their respective longitudinal edges; such as described in U.S. Pat. No. 4,030,277. In this patented construction, a pair of relatively rigid strips are joined together by a flexible intermediate strip. The flexible intermediate strip facilitates movement of the shield so that it is capable of easily reversing its position. Joints are located between the intermediate flexibly resilient strip and the rigid strips, and include grooves in the flexible strip which mate with projections on the marginal edges of the rigid strips. Drag shields having this type of construction have been known to fail standard tests required by existing manufacturing lawn mower requirements. For example, one of the tests includes subjecting a shield to a torsion action wherein adjacent panel strips are twisted in a complete revolution relative to one another. Conventional shields, such as described above, have been known to fail such a torsion test. Accordingly, there is a continuing desire to improve upon the overall performance of drags joint assembly, especially, shields, and in particular their ability to withstand the rigorous testing procedures and usages.